70 likes | 176 Views
tth, (h → bb): Signal, Background & Comparisons. Chris Collins-Tooth 25-Jan-2007. Samples. Signal tth(h → bb): 5340 (forced l + ) 5341 (forced l - ) Backgrounds used: 5855 AcerMC gg->ttbb (QCD) 5214 AcerMC gg->ttbb (EW) 5212 MC@NLO/Herwig ttjj (jj=bb removed).
E N D
tth, (h→bb): Signal, Background & Comparisons Chris Collins-Tooth 25-Jan-2007 Chris Collins-Tooth
Samples • Signal tth(h→bb): • 5340 (forced l + ) • 5341 (forced l - ) • Backgrounds used: • 5855 AcerMC gg->ttbb (QCD) • 5214 AcerMC gg->ttbb (EW) • 5212 MC@NLO/Herwig ttjj (jj=bb removed). Chris Collins-Tooth
Signal and BG Efficiencies. • Latest “full sim” is Compared to Cammin [ATL-PHYS-2003-024] • On the whole encouraging. • Problem with ttjj • many events had >=4 unique b-quarks • Had to remove them, as ttjj(jj=bb) ttbb Chris Collins-Tooth
Signal and BG Efficiencies. higher jet mult. in MC@NLO? • Latest “full sim” is Compared to Cammin [ATL-PHYS-2003-024] • On the whole encouraging. • Problem with ttjj • many events had >=4 unique b-quarks • Had to remove them, as ttjj(jj=bb) ttbb Chris Collins-Tooth
Signal and BG Efficiencies. higher jet mult. in MC@NLO? cut on 2 tops too harsh? • Latest “full sim” is Compared to Cammin [ATL-PHYS-2003-024] • On the whole encouraging. • Problem with ttjj • many events had >=4 unique b-quarks • Had to remove them, as ttjj(jj=bb) ttbb Chris Collins-Tooth
Moving on..... • Look at signal and BG normalised to 30 fb-1 • Problem: BG samples not big enough! • No sensible distributions yet! Chris Collins-Tooth
Optimisations/Cuts.. • Lots of cut optimisations to consider; also new cuts like PtJ1/J2>50/20 GeV on bJets forming Higgs Chris Collins-Tooth